Extension Qr Code

by caffeinelabs362f51ae96f0No license2 starsListed Oct 8, 2026Updated Oct 8, 2026Repository updated today

QR code scanner using the camera.

Instructions onlySoftware Development
AI-generated overview

Adds camera-based QR code scanning to Caffeine AI apps via a prefabricated React hook.

What it does
This skill documents how to add QR code scanning with the device camera to a Caffeine AI application. It describes a prefabricated React hook, useQRScanner, that wraps a camera component and uses jsQR for decoding, exposing scan results, camera state, and controls such as start, stop, switch camera, clear, and retry. It also provides a usage example showing video and canvas refs, result rendering, and error display.
When to use it
Use it when building a Caffeine AI app that needs to read QR codes through the device camera. It suits frontends that require camera preview, scan history, camera switching, and error handling around scanning.
Requirements
Requires the npm packages @caffeineai/qr-code and @caffeineai/camera, a React frontend, and camera access in the browser; jsQR is loaded from a CDN by default. No scripts are shipped; it is instructions only.

QR Code Scanner

QR code scanner extension for Caffeine AI.

Overview

This skill adds QR code scanning using the device camera. Built on top of the camera component with jsQR for decoding.

Frontend

For QR code scanner support:

There is a prefabricated React hook imported from @caffeinelabs/qr-code that cannot be modified.

typescript
import { RefObject } from 'react';import { CameraConfig, CameraError } from '@caffeineai/camera';
export interface QRResult {  // The decoded QR code data  data: string;  // Timestamp when the QR code was scanned  timestamp: number;}
export interface QRScannerConfig extends CameraConfig {  // How often to scan for QR codes in milliseconds (default: 100)  scanInterval?: number;  // Maximum number of results to keep in history (default: 10)  maxResults?: number;  // URL to load jsQR library from (default: jsdelivr CDN)  jsQRUrl?: string;}
export interface UseQRScannerReturn {  // Array of scanned QR codes (newest first)  qrResults: QRResult[];  // Whether currently scanning for QR codes  isScanning: boolean;  // Whether jsQR library has been loaded  jsQRLoaded: boolean;    // Camera state (pass-through from useCamera)  isActive: boolean;  isSupported: boolean | null;  error: CameraError | null;  isLoading: boolean;  currentFacingMode: 'user' | 'environment';    // Start camera and begin scanning - returns true on success  startScanning: () => Promise<boolean>;  // Stop scanning and camera  stopScanning: () => Promise<void>;  // Switch camera facing mode - returns true on success  switchCamera: () => Promise<boolean>;  // Clear all scan results  clearResults: () => void;  // Reset scanner state (stop scanning and clear results)  reset: () => void;  // Retry camera initialization after error - returns true on success  retry: () => Promise<boolean>;    // Ref to attach to video element for camera preview  videoRef: RefObject<HTMLVideoElement>;  // Ref to attach to canvas element used for QR processing (can be hidden)  canvasRef: RefObject<HTMLCanvasElement>;    // Computed state  // Whether scanner is ready to use (jsQR loaded and camera supported)  isReady: boolean;  // Whether scanning can be started (ready + not loading)  canStartScanning: boolean;}
export declare function useQRScanner(config?: QRScannerConfig): UseQRScannerReturn;

Usage example:

typescript
import { useQRScanner } from '@caffeineai/qr-code';
function QRScannerComponent() {    const {         qrResults,        isScanning,        isActive,        isSupported,        error,        isLoading,        canStartScanning,        startScanning,        stopScanning,        switchCamera,        clearResults,        videoRef,        canvasRef     } = useQRScanner({         facingMode: 'environment',        scanInterval: 100,        maxResults: 5    });
    if (isSupported === false) {        return <div>Camera not supported</div>;    }
    return (        <div>            <video                 ref={videoRef}                 style={{ width: '100%', height: 'auto' }}                playsInline                muted            />            <canvas ref={canvasRef} style={{ display: 'none' }} />                        {error && <div>Error: {error.message}</div>}                        <div>                <button onClick={startScanning} disabled={!canStartScanning}>                    Start Scanning                </button>                <button onClick={stopScanning} disabled={isLoading || !isActive}>                    Stop Scanning                </button>                {/* Only show switch camera on mobile */}                {/Android|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent) && (                    <button onClick={switchCamera} disabled={isLoading || !isActive}>                        Switch Camera                    </button>                )}            </div>                        <div>                <h3>Results {qrResults.length > 0 && <button onClick={clearResults}>Clear</button>}</h3>                {qrResults.map(result => (                    <div key={result.timestamp}>                        <small>{new Date(result.timestamp).toLocaleTimeString()}</small>                        <p>{result.data}</p>                    </div>                ))}            </div>        </div>    );}

Properly display QR scanner error messages in the app.

Source and attribution

Source:caffeinelabs/skillsinskills/extension-qr-codeat commit362f51a

License: No license

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